New Server - Completely Clueless!

I operate a small web design firm and I've decided to jump in with both feet and get a dedicated server for my clients.

I have no idea what I'm doing.

I've been issued a server (RHEL, Plesk 7.5) and don't know where to start. The manual for administrators doesn't give step by step suff on what to do either. Here's my setup so far:

Server has 10 available IP's. Just one seems to be set up at present and it's shared. I guess this is the server's main IP address?

I added two further IP's thinking I might need them for nameservers?

I've gone through the manual and "configured" everything like system time, sessions, passwords etc.

Let's say the hostname is sv1.server1.net. I've got a domain name with enom (server1.net) too.

When I first logged in Plesk created a default account called "My Domains" to which I added the domain server1.net and created hosting for.

Now I'm stuck. I guess now I need to create nameservers. How should I do that? As this is my server do I need to "register" nameservers with my registrar on the domain server1.net? I at least know how to do that if I have to

The server should already be doing DNS for the domain you created. Now you need to register your server with your registrar as a nameserver. And point your domain to your newly registered nameservers and everything is good to go.

If you are going to run multiple domains on the same IP then you would want to use the IP as a shared IP.

If you are going to run one domain w/ SSL or anonymous FTP then you want to setup the IP address for that domain as an exclusive IP since you can only run one SSL and/or Anonymous FTP on each IP address.